藻蓝蛋白对大鼠脑缺血再灌注损伤的保护作用及对Caspase-3 mRNA表达的影响

Protection of phycocyanin on the neurons and its effects on the expression of Caspase-3 genes after cerebral ischemia-reperfusion in rats

目的 探讨藻蓝蛋白对大鼠脑缺血再灌注损伤的保护作用及对Caspase-3mRNA表达的影响。方法 应用线栓法建立大鼠大脑中动脉阻塞再灌注（MCAC）／R）模型，随机分为假手术组4只、对照组40只和治疗组40只，应用藻蓝蛋白进行干预治疗，通过Bederson法评价大鼠的神经功能缺失症状．氯化三苯基四氮唑染色测量脑梗塞体积．原位杂交技术检测脑缺血再灌注后不同时段Caspase-3mRNA的表达。结果 脑缺血再灌注24～48h．治疗组神经功能缺损评分和脑梗死体积明显低于对照组。脑缺血再灌注6h，对照组Caspase-3mRNA阳性细胞数开始增加，至再灌注24h达高峰．2d后逐渐减少，至14d仍有表达。治疗组Caspase-3mRNA阳性细胞的数量相对较少，其变化规律与对照组相似，同一时间点相比较均显著低于对照组。结论 藻蓝蛋白可下调Caspase-3mRNA的表达，对脑缺血再灌注损伤有显著保护作用。

Objective To study the protection of phycocyanin on the neurons and the expression of Caspase-3 genes after cerebral ischemia-reperfusion in rats. Methods The model of middle cerebral artery occlusion/reperfusion （MCAO/R） was established using intraluminal filament method. All 84 rats were randomly divided into sham operation group （4 cases）, control group （40 cases） and therapeutic group （40 cases） treated by phycocyanin. The nervous functional deficit score was evaluated by Bederson＇s testing, the cererbral infarction volume was measured using 2,3,5-triphenyhetrazolium chloride （TTC） staining, and the expression of Caspase-3 mRNA was determined by in situ hybridization at regular intervals after ischemic reperfusion. Results Phycocyanin could improve nervous functional deficit score and reduce the cerebral infarction volume during 24 ～48h after cerebral ischemia-reperfusion in rats. In the control group, the upregulalion of Caspase-3 mRNAbegan 6h after reperfusion, reached its maximum at 24h and subsided gradually from 48h to 14d. In the therapeutic group, the time-phase pattern of Caspase-3 mRNA expression was similar to that in the control group, and the number of caspas-3-positive cells were significantly lower than that in the control group at the same time. Conclusions Phycocyanin could inhibit the over-expression of Caspase-3 mRNA in neurons, and might play an important role in protecting ischemic reperfusion injury in rats.